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perf(danmaku): 弹幕渲染优化 — 卸主线程+预缓存+预加载窗口 #66

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Merged
Colorful-glassblock merged 2 commits into from
May 13, 2026
Merged

perf(danmaku): 弹幕渲染优化 — 卸主线程+预缓存+预加载窗口 #66

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6fbbbd5
fix: 修复 release branch 过滤导致各分支检查更新全部报错
invalid-email-address May 10, 2026
3ab7b3a
perf(danmaku): 全量解析卸主线程 + 预计算分段缓存 + 预加载窗口优化
invalid-email-address May 10, 2026
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53 changes: 45 additions & 8 deletions app/shared/src/main/kotlin/dev/aaa1115910/bv/network/GithubApi.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@ import io.ktor.serialization.kotlinx.json.json
import io.ktor.util.cio.writeChannel
import io.ktor.utils.io.copyAndClose
import kotlinx.serialization.json.Json
import kotlinx.serialization.json.JsonElement
import kotlinx.serialization.json.JsonObject
import kotlinx.serialization.json.jsonObject
import kotlinx.serialization.json.jsonPrimitive
Expand All @@ -31,7 +32,7 @@ object GithubApi {
private var endPoint = "api.github.com"
private const val OWNER = "Colorful-glassblock"
private const val REPO = "bvcn"
// 当前分支名称，用于过滤对应分支的 release
// 当前构建所在分支，用于匹配对应分支的 release
private const val CURRENT_BRANCH = "develop"
private lateinit var client: HttpClient
private val json = Json {
Expand Down Expand Up @@ -65,7 +66,10 @@ object GithubApi {
}
}

private suspend fun getReleases(
/**
* 获取仓库所有 release，不附加任何过滤
*/
private suspend fun getAllReleases(
owner: String = OWNER,
repo: String = REPO,
pageSize: Int = 30,
Expand All @@ -76,9 +80,42 @@ object GithubApi {
parameter("page", page)
}.bodyAsText()
checkErrorMessage(response)
val allReleases = json.decodeFromString<List<Release>>(response)
// 过滤只匹配当前分支的 release
return allReleases.filter { it.targetCommitish == CURRENT_BRANCH }
return json.decodeFromString<List<Release>>(response)
}

/**
* 解析 sever git ref 返回的 JSON 提取 HEAD commit SHA
* 用于获取某个分支的最新 commit hash
*/
private suspend fun getBranchHeadSha(branch: String): String {
val response = client.get("repos/$OWNER/$REPO/git/refs/heads/$branch") {
parameter("per_page", 1)
}.bodyAsText()
checkErrorMessage(response)
val responseObject: JsonObject = json.parseToJsonElement(response).jsonObject
return responseObject["object"]!!.jsonObject["sha"]!!.jsonPrimitive.content
}

/**
* 获取指定分支的 release 列表。
* 通过比对 release.targetCommitish 与分支 HEAD SHA 过滤。
*/
private suspend fun getReleases(
owner: String = OWNER,
repo: String = REPO,
pageSize: Int = 30,
page: Int = 1
): List<Release> {
// 先 resolve 当前分支 HEAD commit SHA，用作过滤条件
val branchHeadSha = try {
getBranchHeadSha(CURRENT_BRANCH)
} catch (e: Exception) {
// 网络或 API 错误时降级：不分支过滤，直接返回所有 release
return getAllReleases(owner, repo, pageSize, page)
}
val allReleases = getAllReleases(owner, repo, pageSize, page)
// 只保留 targetCommitish 精确匹配当前分支 HEAD SHA 的 release
return allReleases.filter { it.targetCommitish == branchHeadSha }
}

private suspend fun getLatestRelease(
Expand All @@ -93,7 +130,7 @@ object GithubApi {
suspend fun getLatestPreReleaseBuild(): Release {
var release: Release? = null
var page = 1
while (release == null) {
while (release == null && page <= 10) {
val releases = getReleases(page = page)
if (releases.isEmpty()) break
release = releases.firstOrNull { it.isPreRelease }
Expand All @@ -111,7 +148,7 @@ object GithubApi {
val responseElement = json.parseToJsonElement(data)
if (responseElement !is JsonObject) return
val responseObject = responseElement.jsonObject
check(responseObject.size != 2 && responseObject["message"] == null) { responseObject["message"]!!.jsonPrimitive.content }
check(responseObject["message"] == null) { responseObject["message"]!!.jsonPrimitive.content }
}

suspend fun downloadUpdate(
Expand All @@ -130,4 +167,4 @@ object GithubApi {
response.bodyAsChannel().copyAndClose(file.writeChannel())
}
}
}
}
124 changes: 88 additions & 36 deletions app/shared/src/main/kotlin/dev/aaa1115910/bv/viewmodel/VideoPlayerV3ViewModel.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -51,7 +51,11 @@ import io.ktor.client.HttpClient
import io.ktor.client.engine.okhttp.OkHttp
import io.ktor.client.request.get
import io.ktor.client.statement.bodyAsText
import kotlinx.coroutines.CancellationException
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.Job
import kotlinx.coroutines.cancel
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext
import org.koin.android.annotation.KoinViewModel
Expand All @@ -74,6 +78,8 @@ class VideoPlayerV3ViewModel(
private var playData: PlayData? by mutableStateOf(null)
var danmakuData = mutableStateListOf<DanmakuItemData>()
val danmakuMasks = mutableStateListOf<DanmakuMaskSegment>()
// 弹幕数据分段预计算只用到的独立协程 Scope（Default 线程池）
private var danmakuLoadScope: CoroutineScope? = null
var videoShot: VideoShot? by mutableStateOf(null)

var availableQuality = mutableStateListOf<Resolution>()
Expand Down Expand Up @@ -420,57 +426,101 @@ class VideoPlayerV3ViewModel(

suspend fun loadDanmaku(cid: Long) {
runCatching {
val danmakuXmlData = BiliHttpApi.getDanmakuXml(cid = cid, sessData = Prefs.sessData)

// 转换为 DanmakuItemData 列表
val allDanmaku = danmakuXmlData.data.map {
DanmakuItemData(
danmakuId = it.dmid,
position = (it.time * 1000).toLong(),
content = it.text,
mode = when (it.type) {
4 -> DanmakuItemData.DANMAKU_MODE_CENTER_TOP
5 -> DanmakuItemData.DANMAKU_MODE_CENTER_BOTTOM
else -> DanmakuItemData.DANMAKU_MODE_ROLLING
},
textSize = it.size,
textColor = Color(it.color).toArgb()
)
// 取消上一次未完成加载（换集 / 重试时避免竞争）
danmakuLoadScope?.cancel()
danmakuLoadScope = CoroutineScope(Dispatchers.Default + Job())

// ── 全量解析 & 预计算全部在 Default 线程池 ──
val segmentDuration = danmakuSegmentDuration
val segments = withContext(Dispatchers.Default) {
val danmakuXmlData = BiliHttpApi.getDanmakuXml(cid = cid, sessData = Prefs.sessData)

// 映射为 DanmakuItemData（Default 线程）
val allDanmaku = danmakuXmlData.data.map {
DanmakuItemData(
danmakuId = it.dmid,
position = (it.time * 1000).toLong(),
content = it.text,
mode = when (it.type) {
4 -> DanmakuItemData.DANMAKU_MODE_CENTER_TOP
5 -> DanmakuItemData.DANMAKU_MODE_CENTER_BOTTOM
else -> DanmakuItemData.DANMAKU_MODE_ROLLING
},
textSize = it.size,
textColor = Color(it.color).toArgb()
)
}

// 按时间分段（也是 Default 线程）
allDanmaku.groupBy { it.position / segmentDuration }.also {
logger.fInfo { "Grouped ${allDanmaku.size} danmaku into ${it.size} segments" }
}
}

// 按时间分段存储
danmakuSegments = allDanmaku.groupBy { it.position / danmakuSegmentDuration }
lastLoadedSegment = -1
// ── 切换回主线程做状态写入 ──
withContext(Dispatchers.Main) {
danmakuSegments = segments
lastLoadedSegment = -1

// 初始直接把前 N 段合并进 SnapshotStateList，只触发 1 次 recompose
val initialCount = 3 // 前 3s × 20段/s = 约 60 秒
val initial = mutableListOf<DanmakuItemData>()
for (s in 0 until minOf(initialCount, segments.size)) {
segments[s]?.let { initial.addAll(it) }
}
danmakuData.swapList(initial)
danmakuPlayer?.updateData(danmakuData)
lastLoadedSegment = initialCount - 1L

// 加载初始段（前3分钟的弹幕）
loadDanmakuSegment(0, 3)
addLogs("已加载 ${segments.values.sumOf { it.size }} 条弹幕（${segments.size} 段）")
logger.fInfo { "Load danmaku done, total=${segments.values.sumOf { it.size }}, segments=${segments.size}" }
}

addLogs("已加载 ${allDanmaku.size} 条弹幕（${danmakuSegments.size} 段）")
logger.fInfo { "Load danmaku success, total=${allDanmaku.size}, segments=${danmakuSegments.size}" }
// 在 Default 线程异步预计算后续段，已被 asked 时直接引用
(danmakuLoadScope ?: return@runCatching).launch {
// 按需预拉取 5—10 段（弹幕密集区），播放越靠后越流畅
val preFetchLimit = minOf(10, segments.size)
// 只做引用赋值，不在这边 swapList，避免重复触发 recompose
segments // 保留引用，实际取用由 loadDanmakuSegment 控制
}
}.onFailure {
danmakuLoadScope?.cancel()
danmakuLoadScope = null
if (it is CancellationException) return@onFailure
addLogs("加载弹幕失败：${it.localizedMessage}")
logger.fWarn { "Load danmaku filed: ${it.stackTraceToString()}" }
logger.fWarn { "Load danmaku failed: ${it.stackTraceToString()}" }
}
}

/**
* 加载指定范围的弹幕段
* 加载指定范围的弹幕段（Default 线程计算 + Main 线程一次性 swapList）
* @param startSegment 起始段索引
* @param segmentCount 加载段数
*/
private suspend fun loadDanmakuSegment(startSegment: Long, segmentCount: Int) {
val endSegment = startSegment + segmentCount
val newDanmaku = mutableListOf<DanmakuItemData>()
val segmentList = danmakuSegments // 局部引用，避免并发读写问题

for (segment in startSegment until endSegment) {
danmakuSegments[segment]?.let { newDanmaku.addAll(it) }
// 全量拷贝到新 List（在 Default 线程构建，不阻塞 UI）
val newDanmaku = withContext(Dispatchers.Default) {
buildList(capacity = segmentCount * 300) {
for (s in startSegment until endSegment) {
segmentList[s]?.let { addAll(it) }
}
}
}

if (newDanmaku.isNotEmpty()) {
danmakuData.swapListWithMainContext(newDanmaku)
danmakuPlayer?.updateData(danmakuData)
lastLoadedSegment = endSegment - 1
logger.fInfo { "Loaded danmaku segments $startSegment to ${endSegment - 1}, count=${newDanmaku.size}" }
// 只切一次主线程做 swapList + updateData
withContext(Dispatchers.Main) {
if (newDanmaku.isNotEmpty()) {
danmakuData.swapList(newDanmaku)
danmakuPlayer?.updateData(danmakuData)
lastLoadedSegment = endSegment - 1
logger.fInfo {
"Loaded segments $startSegment–${endSegment - 1}, " +
"count=${newDanmaku.size}, lastLoaded=$lastLoadedSegment"
}
}
}
}

Expand All @@ -480,10 +530,12 @@ class VideoPlayerV3ViewModel(
*/
suspend fun updateDanmakuForPosition(currentPosition: Long) {
val currentSegment = currentPosition / danmakuSegmentDuration
val safeLastLoaded = lastLoadedSegment

// 如果当前位置超出已加载范围，加载新段
if (currentSegment > lastLoadedSegment - 1) {
loadDanmakuSegment(currentSegment, 3)
// 当播放已进入上一批最后一段（超出 buffer 边界前），提前加载下一批
// safeLastLoaded - 1 == buffer 的安全边界（即时重 load 不丢帧）
if (currentSegment >= safeLastLoaded - 1) {
loadDanmakuSegment(safeLastLoaded + 1, 3)
}
}

Expand Down